No word yet on why: did he jump or was he pushed? Keith Olbermann, highest rated host on cable network MSNBC, announced at the end of his show “Countdown” tonight that it’s over.

MSNBC followed up with a statement:

MSNBC and Keith Olbermann have ended their contract. The last broadcast of “Countdown with Keith Olbermann” will be this evening. MSNBC thanks Keith for his integral role in MSNBC’s success and we wish him well in his future endeavors.

Starting Monday, Lawrence O’Donnell is the lead-in to Rachel Maddow, followed by Ed Schultz.

Joanne Ostrow has been watching TV since before "reality" required quotation marks. "Hill Street Blues" was life-changing. If Dickens, Twain or Agatha Christie were alive today, they'd be writing for television. And proud of it.